Manually controlled straightening systems for bar steel which are used in steelworks and processing plants are usually equipped with a motor-driven roller way for moving and straightening the bar through the straightening press in order to straighten it. The bars to be straightened usually have a round section with a diameter between 80 and 450 mm and lengths between 2 m and 30 m. They are transported rolling in a horizontal position on the so-called roller ways, from a feed position into the straightening position and from there into a discharge position, that is to say also in the region of the processing section. Bend-straightening machines of the generic type are described, inter alia, in DE 25 24 310 A and in documents DE 197 25 033 C1 and DE 20 2006 008 001 U. The bend-straightening machine acts in the horizontal direction on the bar steel resting on the roller way during the entire procedure. As a result, by pushing forward and backward on the roller way any longitudinal position of the workpiece can be bend-straightened. The circumferential angular position of the workpiece is changed, for example, by so-called chain turning devices, with the result that the bend-straightening is possible not only in all longitudinal positions but also in all angular or circumferential positions of the workpiece. Such bend-straightening machines are offered, for example, by Röcher GmbH & Co. KG in Netphen. The bend-straightening of long workpieces resting on a roller way has accuracy limits due, inter alia, to the fact that the elastic resetting of the long workpiece after each bending step is impeded by frictional forces between the workpiece and the roller way.
Preference has therefore been given to bend-straightening machines (DE 101 44 135 C1) in which the long workpiece is supported vertically only at its ends in different workpiece positions at least between the bend-straightening steps. For this purpose, use is made of, in each case, a grasping device which also permits the workpiece to rotate about its longitudinal axis and which defines a processing section in the straightening press. The straightening press can be moved into the respectively desired bend-straightening positions along the workpiece which is supported only at its ends. In order to grasp workpieces of differing lengths, the grasping devices have variable spacing along the processing section. The workpiece which is to be processed can basically be inserted into its supports on the grasping devices by means of a crane device. This work-intensive charging process of the bend-straightening machine can be simplified by virtue of the fact that the grasping devices have pivoting means which permit a workpiece which is held ready next to the processing section and parallel thereto to be grasped and pivoted, in an approximately 180 degree pivoting step from the feeding-in position transverse with respect to its longitudinal direction into the processing section of the bend-straightening machine. At present, it is conventional to feed radially with the lifting means or the like. The last-mentioned bend-straightening machines from which the invention proceeds are marketed by the applicant as their ASV-L series. The bend-straightening process takes place automatically over the entire length of the workpiece and with high precision.